As a Radio Frequency (RF) circuit in a wireless communication field using a millimeter-wave band is made from a Complementary Metal Oxide Semiconductor (CMOS), study has been undertaken for reducing the size and power of the RF circuit for commercialization thereof.
In specific low power wireless communication using the millimeter-wave band such as a 60 GHz band, the strength of transmission radio waves is defined. In a high frequency region such as the millimeter-wave band, the characteristics greatly change depending on a change in a process, a temperature, and a power supply voltage of a transistor. Thus, it is necessary to control the power of a high frequency transmission signal. In other words, since the power is measured by monitoring the high frequency transmission signal, it is necessary to control the power of the high frequency transmission signal to be a constant value.
As a related art of controlling the power of the high frequency transmission signal, a TDMA transmitter has been known which measures the power of the high frequency transmission signal which is amplified by a power amplifier and obtains desired constant power (for example, see Patent Literature 1).
Further, if there is a DC offset in an in-phase signal (I signal: In-phase) and a quadrature signal (Q signal: Quadrature) in a quadrature modulator that generates a high frequency transmission signal, carrier leakage occurs in the high frequency transmission signal. Further, if there is an imbalance in the amplitudes and the phases of the I and Q signals in the quadrature modulator that generates the high frequency transmission signal, image leakage occurs in the high frequency transmission signal.
A transmission apparatus has been known which adjusts respective amplitudes and phases of an I signal and a Q signal by using a detection output obtained by detecting a portion of a high frequency transmission signal which is generated by a quadrature modulator so as to reduce carrier leakage and image leakage occurring in the high frequency transmission signal (for example, see Non Patent Literature 1).